How we connect: discovering the human place in the organic world. Classification the ordering of organisms into categories, such as orders, families, and genera, to show evolutionary relationships. Chordata the phylum of the animal kingdom that includes vertebrate all animals with a nerve cord, gill slits and a supporting cord along the back. Vertebrates animals with segmented bony spinal columns; includes fishes, amphibians, reptiles (including birds), and mammals have developed brain and paired sensory structures for sight, smell, and balance 5 classes: 1. Taxonomy field that specializes in establishing the rules of classification: organisms are classified traditionally to physical similarities, similarities must reflect evolutionary descent. Homologies similarities between organisms based on descent from a common ancestor. Analogies similarities between organisms based strictly on common function, with no assumed common evolutionary descent. Homoplasy the separate evolutionary development of similar characteristics in different groups of organisms.